A variety of techniques are known in the surgical arts in which a plurality of surgical implants, e.g. bone prostheses, are inserted into the bone of a patient. Commonly, the goal of such a technique is the stabilization and subsequent healing of a fracture across which a plurality of bone prostheses, e.g. screws, nails or pins, are placed, preferably in a mutually parallel relationship. In one technique in common use, especially in the fixation of fractures of the femoral neck, non-cannulated Knowles pins threaded at their proximal ends are drilled by the surgeon into position across the fracture. This is essentially a "free-hand" procedure aided by X-rays taken in the anterior-posterior and lateral planes before and after pin placement; thus correct placement requires the exercise of a considerable amount of technical skill. Incorrectly positioned pins must be removed, thereby leaving an undesired bore in the patient's bone, and re-drilled into the correct position. The use of jigs to insure the proper placement of Knowles pins is complicated by the fact that these pins are headed at their distal ends to provide means for applying compression to the fragments of the fractured bone. Replacement of a correctly positioned Knowles pin with one of a different length may also be problematic in cancellous bone because of the difficulty in following the existing bore in the spongy bone tissue.
Certain of the difficulties mentioned above can be alleviated by the use of cannulated bone screws inserted over previously inserted guide wires (see for example U.S. Pat. No. 2,570,465), with the cannulation being as narrow as possible to provide the necessary screw strength with a minimum screw outer diameter. Most commonly, the guide wires are drilled into position by the same "free-hand" method described above in connection with Knowles pinning. The consequent difficulties in properly positioning the guide wires are compounded by the tendency of the narrow wires to wobble and bend as they are drilled into position.
A number of instruments intended for positively directing the correct placement into bone of prostheses or guide wires therefor have been disclosed in the prior art. As a rule, these instruments suffer in use from one or more of the following drawbacks: (a) they are complex in design and cumbersome and time-consuming to operate; (b) they require unnecessary destruction of healthy tissue (e.g., lengthy incisions, fixations of instruments to bone with screws) during the surgical intervention; or (c) they do not provide for universal positioning (in terms of both linear displacement and angulation) of the prosthesis or guide wire in the patient's bone.